Decidable classes of documents for XPath

Vince Bárány (1, 2) , Mikołaj Bojańczyk (2) , Diego Figueira (3, 2) , Paweł Parys (2)

1 TU Darmstadt - Technische Universität Darmstadt - Technical University of Darmstadt
2 MIMUW - Faculty of Mathematics, Informatics, and Mechanics [Warsaw]
3 LFCS - Laboratory for the Foundations of Computer Science [Edinburgh]

We study the satisfiability problem for XPath over XML documents of bounded depth. We define two parameters, called match width and braid width, that assign a number to any class of documents. We show that for all k, satisfiability for XPath restricted to bounded depth documents with match width at most k is decidable; and that XPath is undecidable on any class of documents with unbounded braid width. We conjecture that these two parameters are equivalent, in the sense that a class of documents has bounded match width iff it has bounded braid width.

Mots clés: XPath; XML; class automata; data trees; data words; satisfiability

Domaines: Base de données [cs.DB]; Théorie et langage formel [cs.FL]; Mathématique discrète [cs.DM]; Logique en informatique [cs.LO]

Vince Bárány, Mikołaj Bojańczyk, Diego Figueira, Paweł Parys. Decidable classes of documents for XPath. IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS), 2012, Hyderabad, India. pp.99-111. ⟨hal-01799733⟩